NONDESTRUCTIVE INSPECTION OF A STRUCTURE INCLUDING THE ANALYSIS OF CAVITY ELECTROMAGNETIC FIELD RESPONSE

• US 20090108211A1
• Filed: 10/26/2007
• Published: 04/30/2009
• Est. Priority Date: 10/26/2007
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Bommer, Jason Philip, Whetham, William John
• Granted Patent: US 7,830,523 B2
• Time in Patent Office: Days
• US Class Current: 250/395
• CPC Class Codes: G01N 22/02 Investigating the presence of flaws

Abstract

Nondestructive inspection (NDI) on a structure having a cavity includes exciting the structure with electromagnetic radiation and analyzing the cavity'"'"'s electromagnetic field response to detect a state change of the structure.

Claims

1. A method comprising performing NDI on a structure having a cavity, the NDI including exciting the structure with electromagnetic radiation and analyzing the cavity'"'"'s electromagnetic field response to detect a state change of the structure.

2. The method of claim 1, wherein the structure is excited to exhibit the characteristics of an electromagnetic waveguide.

3. The method of claim 1, wherein the structure is excited to exhibit the characteristics of a cavity resonator.

4. The method of claim 1, wherein the excitation has a dominant electric field component.

5. The method of claim 1, wherein the excitation has a dominant magnetic field component.

6. The method of claim 1, wherein detecting the state change includes correlating the cavity response to a state change of the structure.

7. The method of claim 1, wherein detecting the state change includes measuring the cavity response;

and comparing the measurements to baseline data for the structure.

8. The method of claim 1, further comprising providing an indication of structural health of the structure after the cavity response has been analyzed.

9. The method of claim 8, wherein the NDI is performed continuously and the indication is provided automatically.

10. The method of claim 1, wherein the structure is an aircraft structure;

and wherein the NDI is performed in-flight.

11. The method of claim 10, wherein the NDI is performed following a lightning strike.

12. A method of analyzing structural health of an aircraft, the method comprising exciting different aircraft structures exhibiting RF characteristics with electromagnetic radiation and analyzing cavity responses to detect state changes of the structures.

13. The method of claim 12, wherein the excitation and analysis are performed in-flight.

14. The method of claim 12, wherein the excitation and analysis are performed following a lightning strike.

15. The method of claim 12, wherein the excitation and analysis are performed following severe turbulence.

16. The method of claim 12, further comprising identifying those structures whose states changed.

17. The method of claim 12, further comprising identifying the nature and degree of any state changes.

18. The method of claim 12, wherein analyzing the cavity responses includes correlating measurements of the cavity responses to baseline data for the aircraft structures.

19. Apparatus comprising an analyzer for performing NDI on a structure having a cavity, the analyzer analyzing measurements of cavity responses to electromagnetic excitation of the structure, the analysis performed to detect a state change of the structure.

20. The apparatus of claim 19, further comprising at least one element for providing the electromagnetic excitation and measuring the cavity responses.

21. An aircraft comprising a plurality of structures having cavities;

and a system for performing NDI on the structures, the system including

electromagnetic excitation apparatus for exciting those structures exhibiting RF characteristics with electromagnetic radiation; and

field response measurement apparatus for measuring field responses to the electromagnetic excitation, the measurements providing information about any state changes of the structures.

22. The aircraft of claim 21, further comprising an analyzer for analyzing the measurements to detect any state changes of the structures.

23. The aircraft of claim 21, wherein the excitation apparatus and the measurement apparatus are operable during flight.

24. The aircraft of claim 21, wherein the state changes include those state changes that relate to structural health of the aircraft.

25. The aircraft of claim 21, further comprising a system for suggesting an appropriate action in response to those state changes that relate to the structural health of the aircraft.